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Deformation behaviors of Cu bicrystals with an inclined twin boundary at multiple scales

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Journal of Materials Science & Technology 2017年第7期33卷 698-702页

作者： l.l.li z.J.zhang P.zhang J.Tan J.B.Yang z.F.zhang Shenyaag National laboratory for Materials Science lastitute of Metal Research Chinese Academy of Sciences Shenyaag 110016 China

Cu bicrystals of different sizes with a sole twin boundary（TB） inclined at 45？with respect to the loading direction were deformed under unidirectional and cyclic loading, respectively. It is found that the slip bands（SBs） parallel to the TB can be activated near the TB at all scales without obeying the Schmid＇s *** is concerned with the local stress enhancement in the macroscale while it is more closely related to the scarce dislocation sources in the microscale. Moreover, a wedge-shaped zone formed near the TB in the microscale ascribed to the limited specimen size.

关键词： Bicrystal Micropillar Twin boundary Schmid factors Size effect

Influencing mechanism of pre-existing nanoscale Al5Fe2 phase on Mg-Fe interface in friction stir spot welded Al-free zK60-Q235 joint

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Journal of Materials Science & Technology 2020年第7期42卷 220-228页

作者： R.z.Xu Q.Yang D.R.Ni B.l.Xiao C.z.liu z.Y.Ma Institute of Metal Research Chinese Academy of SciencesShenyang110016China College of Material Science and Engineering Shenyang Aerospace UniversityShenyang110136China Department of Materials Science and Engineering University of Illinois at Urbana-Champaign1304 W Green StUrbanaIL61801United States Fredrick Seitz Materials Research laboratory University of Illinois at Urbana-Champaign104 S Goodwin AveUrbanaIL61801United States

Al-free zK60 magnesium (Mg) alloy sheet was selected as substrate material of Mg-steel pinless friction stir spot welding (FSSW), avoiding the effect of the Al element in the substrate on the alloying reaction of Mg-iron (Fe) interface. The sound FSSW joint of zK60 Mg alloy and Q235 steel with a hot-dipped aluminum (Al)-containing zinc (zn) coating was successfully realized. The detailed microstructural examinations proved that Al5Fe2 phase at the Mg-Fe interface came from the pre-existing Al5Fe2 phase in the coating and acted as the transition layer for promoting the metallurgical bonding of Mg and Fe. The interfaces with well-matched lattice sites among Fe, Al5Fe2 and Mg were formed during FSSW. A low energy interface with good match of lattice sites ((002)Al5Fe2//(110)Fe, [110]Al5Fe2//[113]Fe) between Al5Fe2 and Fe was identified. For the interface between Al5Fe2 and Mg, an orientation relationship of (622)Al5Fe2//(3112)Mgand[158]Al5Fe2//[2423]Mg was observed. The tensile-shear load of the zK60-steel joint could reach 4.6 kN. Moreover, the joint fracture occurred at the interface between the Al5Fe2 layer and the Mg alloy substrate, suggesting the brittle fracture characteristic.

关键词： Dissimilar welding Friction stir spot welding Magnesium alloys Steels zinc coating

Dispersion and Damage of Carbon Nanotubes in Carbon Nanotube/7055Al Composites During High-Energy Ball Milling Process

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Acta Metallurgica Sinica(English letters) 2021年第2期34卷 196-204页

作者： S.Bi B.l.Xiao z.H.Ji B.S.liu z.Y.liu z.Y.Ma Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China School of Material Science and Engineering University of Science and Technology of China72 Wenhua RoadShenyang 110016China AVIC Manufacturing Technology Institute Beijing 100024China

High-energy ball milling(HEBM)combined with powder metallurgy route was used to fabricate carbon nanotube(CNT)reinforced 7055 Al *** powder morphology evolution processes(HEBM-1 and HEBM-2)were designed to investigate the dispersion and damage of CNTs during HEBM ***-1 evolution process involved powder fl attening,cold-welding and fracture,while HEBM-2 evolution process consisted of powder fl attening and *** HEBM-1,the repetitive fracture and cold-welding process was effective for dispersing ***,the powder fl attening process in HEBM-2 was unsuccessful in dispersing CNTs due to two reasons:(1)the thickness of fl aky Al powders exceeded the critical value,and(2)the clustered CNTs embedded in fl aky Al powders could not be *** of the broadening of D band and the appearance of a new defect-related D’band,product of I D/I G and full width half maximum of D band,rather than I D/I G,was used to evaluate the actual damage of *** indicates that the damage of CNTs was severe in powder fl attening and fracture stages,while the damage of CNTs was small in powder cold-welding stage.

关键词： Metal matrix composites Carbon nanotubes Powder evolution Dispersion and damage Powder metallurgy

人表皮生长因子受体2(HER2)低表达和HER2过表达乳腺癌的鉴别：4种MRI扩散模型的比较研究

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国际医学放射学杂志 2024年第3期 379-380页

作者： C.Mao l.Hu W.Jiang Y.Qiu z.Yang Y.liu 余芸菲

摘要目的确定传统扩散加权成像（DWI）、连续时间随机游走（CTRW）、分数阶微积分（FROC）和拉伸指数模型（SEM）在识别乳腺癌的人表皮生长因子受体2(HER2)表达

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Surface deformation-dependent mechanical properties of bending nanowires:an ab initio core-shell model

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Applied Mathematics and Mechanics(English Edition) 2022年第2期43卷 219-232页

作者： Ye XIAO J.SHANG l.z.KOU Chun lI School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an710072China MIIT Key laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical UniversityXi’an710072China School of Mechanical Medical and Process EngineeringQueensland University of TechnologyBrisbaneQLD4000Australia

An ab initio core-shell model is proposed to evaluate the surface effect in bending nanowires,in which the elastic modulus depends on the surface relaxation and deformation induced by external *** using first-principles calculations based on the density functional theory(DFT),the surface and bulk properties are calculated for Ag,Pb,and Si *** obtained theoretical predictions of the effective Young’s modulus of nanowires agree well with the experimental data,which shows that the fixed-fixed nanowire is stiffened and the cantilevered nanowire is softened as the characteristic size of the cross section ***,the contrastive analysis on the two kinds of nanowires demonstrates that increasing the nanowire aspect ratio would enhance the surface *** present results could be helpful for understanding the size effect in nanowires and designing nanobeam-based devices in nanoelectromechanical systems(NEMSs).

关键词： surface effect density functional theory(DFT) surface relaxation surface stress nanowire

Snap-through of an elastica under bilateral displacement control at a material point

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Acta Mechanica Sinica 2020年第3期36卷 727-734页

作者： Q.Wang H.l.zou z.C.Deng Department of Engineering Mechanics Northwestern Polytechnical UniversityXi'an 710072China

Snap-through phenomenon widely occurs for elastic systems,where the systems lose stability at critical *** snapthrough of an elastica under bilateral displacement control at a material point is studied,by regarding the whole elastica as two components,i.e.,pinned-clamped ***,stiffness-curvature curves of two pinned-clamped elasticas are firstly efficiently located based on the second-order mode,which are used to determine the shapes of two *** transformations are used to assemble two components together to form the whole elastica,which reveals four kinds of *** advantage of this way compared with other methods such as the shooting method is that multiple coexisting solutions can be located accurately.O n the load-deflection curves,four branches correspond to four kinds of shapes and first two branches are symmetrical to the last two branches relative to the original *** the bilateral displacement control,the critical points can only appear at saddle-node bifurcations,which is different to that for the unilateral displacement ***,one critical point is found on the first branch and two critical points are found on the secondary *** addition,the snap-through among different branches can be well explained with these critical points.

关键词： Elastica Snap-through Critical points Buckling Displacement control

Chinese Expert Consensus on the Diagnosis and Treatment of Adult Dermatomyositis (2022)#

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International Journal of Dermatology and Venereology 2024年第3期7卷 163-173页

作者： Cao H. Chen A.-J. Cui Y. Deng D.-Q. Gao X.-H. He Y.-l. Kang X.-J. Jin H.-z. li C.-X. li F. li H.-J. liao W.-J. liu X.-M. lu Q.-J. lu Y. Pan M. Pan W.-H. Shu X.-M. Sun Q. Tang K.-Y. Tao J. Wang Y. Xiao T. zhang F.-R. zhang H.-l. Department of Dermatology Ruijin Hospital Affiliated Shanghai Jiao Tong University School of Medicine Shanghai 200025 China Department of Dermatology First Affiliated Hospital of Chongqing Medical University Chongqing 400042 China Department of Dermatology China-Japan Friendship Hospital Beijing 100029 China Department of Dermatology The Second Affiliated Hospital of Kunming Medical University Yunnan Kunming 650101 China Department of Dermatology The First Hospital of China Medical University Liaoning Shenyang 110001 China Department of Dermatology Beijing Chaoyang Hospital Affiliated to Capital Medical University Beijing 100020 China Department of Dermatology and Venereology People's Hospital of Xinjiang Uygur Autonomous Region Xinjiang Uygur Autonomous Region Urumqi 830001 China Department of Dermatology State Key Laboratory of Complex Severe and Rare Diseases Peking Union Medical College Hospital Chinese Academy of Medical Science Peking Union Medical College Beijing 100730 China Department of Dermatology First Medical Center PLA General Hospital Beijing 100853 China Department of Dermatology Hainan Hospital of PLA General Hospital Hainan Sanya 572013 China Department of Dermatology Xijing Hospital Air Force Medical University Shaanxi Xi'an 710032 China Department of Dermatology Huazhong University of Science and Technology Union Shenzhen Hospital Guangdong Shenzhen 518052 China Hospital for Skin Diseases Institute of Dermatology Chinese Academy of Medical Sciences Peking Union Medical College Jiangsu Nanjing 210042 China Department of Dermatology Jiangsu Province Hospital The First Affiliated Hospital Nanjing Medical University Jiangsu Nanjing 210029 China Department of Dermatology Shanghai Changzheng Hospital Second Affiliated Hospital of Naval Medical University Shanghai 200003 China Department of Rheumatology China-Japan Friendship Hospital Beijing 100029 China Department of Dermatology Qilu Hospital of Shandong Universit

Dermatomyositis, an idiopathic inflammatory myopathy, is characterized by distinctive skin manifestations, proximal muscle weakness, and multiple organ involvement and can be accompanied by malignancies. To provide a reference for dermatologists and clinicians in other relevant fields of clinical practice, experts from the Dermatology Branch of the China International Exchange and Promotion Association for Medical and Health Care and the National Clinical Research Center for Dermatologic and Immunologic Diseases developed this consensus on the diagnosis and treatment of adult dermatomyositis using Chinese and international literature and expert advice. © 2024 Wolters Kluwer Health. All rights reserved.

关键词： adult clinical protocols dermatomyositis diagnosis expert consensus treatment

Revealing the high-frequency attenuation mechanism of polyurea-matrix composites

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Acta Mechanica Sinica 2020年第1期36卷 130-142页

作者： J.Cheng z.l.liu C.C.luo T.li z.J.li Y.Kang z.zhuang Applied Mechanics laboratory School of Aerospace EngineeringTsinghua UniversityBeijing100084China Key laboratory of Advanced Materials of Ministry of Education Department of Chemical EngineeringTsinghua UniversityBeijing100084China School of Materials Science and Engineering Tsinghua UniversityBeijing100084China

In this paper,a method for analyzing the high-frequency attenuation property of polyurea-matrix composites is developed by combining experimental,computational and theoretical ***,the ultrasonic experimental platform is established by solving the difficulties of high-frequency ultrasonic testing as high-frequency signal distortion,insufficient driving voltage and sampling rate failure,to study the dynamic mechanical properties(1-5 MHz)of pure polyurea and polyurea-matrix ***,the influences of composite parameters including the size and volume fraction of inclusions on wave attenuation performance under different frequencies are obtained and further verified by numerical ***,the contribution of inclusions to the wave attenuation performance is also theoretically *** is found that the increase of inclusion volume fraction and inclusion diameter will increase the attenuation coefficient of the *** the attenuation of composites with the inclusions of a 150-μm diameter and 30%as volume fraction can be 82%higher than pure *** amplifying attenuation effect of inclusions is mainly attributed to the scattering effect,which is verified by comparing numerical and theoretical results.

关键词： Polyurea Viscoelastic Dynamic mechanical properties Ultrasound

CONTROl TECHNIQUES FOR DIGESTION IN BAYER PROCESS

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Acta Metallurgica Sinica(English letters) 2000年第6期13卷 1174-1178页

作者： G.Y.Gan l.z.Wang Pingguo Aluminum Company Pingguo 531400China

The control techniques for indirect heating digestion in Bayer process of alumina production were researched and developed. They include controlling chemical composition of slurry to be digested and controlling digestion status and energy consumption. Very good performances and technical and technical and economical figures for digestion process have been obtained by carefully applying these comprehensive control techniques in Pingguo alumina refinery.

关键词： control technique digestion Bayer process